Over the years many remailable or two way envelopes have been designed. However, the majority of the businesses with a need for receiving return mail still provide separate return envelopes for their customers.
There is a greater awareness concerning the conservation of resources and reduction of waste such that many companies are voluntarily making efforts to reduce waste and use resources more efficiently. Therefore, the lack of more wide spread use of two way envelopes is surprising and most likely related to the increased cost and difficulty of use of previously designed two way envelope.
Prior envelopes with second mailing flaps are often difficult to use or can not be used with standard postal equipment (e.g. bar code readers) or office equipment (e.g.) letter openers.
U.S. Pat. No. 3,096,925 teaches a two way envelope that is sealed for a first mailing by a removable tab on an extension from the back of the envelope. Once the tab is removed the extension from the back can be brought further down the front by folding the front and back of the envelope at a lower line across the top. This envelope has many disadvantages. The envelope would be rendered useless if a standard letter opener were used. The user must place the initial address high up near the top of the envelope so that it is covered during the second mailing. This is contrary to standard practice and would be not be usable with bar code scanning techniques.
U.S. Pat. No. 4,308,987 teaches a two way envelope that includes a second mailing panel that is attached to the back of the envelope and stuffed inside the envelope during the first mailing. After the first mailing, the second mailing flap is removed and folded over the first mailing information. The sides of the second mailing flap are contoured to allow removal. Even so, the second mailing flap of this type of envelope is extremely difficult to remove without damage. The flap does not cover the entire front of the envelope. Depending upon how the first user positions the return address, some portion of it may show on the outside of the envelope during the second mailing. U.S. Pat. No. 4,332,346 is similar to the envelope taught in U.S. Pat. No. 4,308,987, however, it also teaches providing a spot of glue to prevent the return flap from rising up prematurely and being cut by a letter opener. The glue makes the second mailing flap even more difficult to remove.
U.S. Pat. Nos. 4,565,317, 4,595,138, 4,730,768, 5,197,663 and 5,224,647 all two way envelopes that include a second mailing panel that is attached to the back of the envelope and stuffed inside the envelope during the first mailing. After the first mailing, the second mailing flap is removed and folded over the first mailing information. In some embodiment the sides of the second mailing flap are contoured to allow removal, in others the flap is folded. Even so, the second mailing flap of this type of envelope is extremely difficult to remove without damage. All of these designs are deficient in that they do not provide a second mailing flap that is extremely easy to fold out and secure.